Piston king expander



I Re. 20,588

Dec. 14-, 1937. TEETOR PISTON RINGBXPANDER Original Filed May 25, 1935 2 Sheets-Sheet l w/c JZZOW f mmzfora %,maM, M WWW 3 E ETOR Dec. 14, 1937.

bility of the ends of the ring;

Reissued Dec. 14, 1937 UNITED STATES 13 Claims.

My invention relates to piston ring expanders for use in connection with and adapted to augment the expanding action of piston rings for internal combustion engines and the like.

One object of my invention is to provide a novel one-piece spring expander formed from a stamping and shaped and bent to provide a plurality of independent, individually operable united by a supporting strip'or band.

Another object of my invention is to provide integral means for connecting the spring members to one edge of the supporting band and spacing them therefrom.

a ring expander having spring elements for exerting the required pressure against a ring to rect pressure against the cylinder wall, the positions of the elements being maintained relative to'the joint of the ring.

A further object is to provide an expander of the character indicated in which the spring elecated closer together because ofthe greater flexi- These and further objects my invention will be set forth in the following specification, reference being'had to the accompanying drawings, and the novel'means'by' which said objects are claims. g

In the drawings:

Figure 1 is aplan view oi'fa" portion of the 1 eii'e ctuat ed will be definitely pointed out in the stamping "from which theexpander; is made;

' j 2isa..perspective'viewof faportion of the device a'fter the parts havebeen bent into posi- 1 Figs. 3andj4 are sectionsalong'the iinesJ-r-S and in Figs 2 and 3, respectively; looking in the direction of the arrows, and showing the projections against which'the spring leaves are adapted to rest; V Fig. 515 a plan view of a portion of a stamping and shows a modified form of means for spacing the spring members and the band;

Fig. 6 is abottom edge elevation showing a further modified form of spacing means;

sertion in the ri v joint;

spring elements that are suitably carried and Another object ofrny invention is to provide cause the latter to bear with'a substantially corments on opposite sides of thering joint are'lovided at their junction with the necks I3.

Fig. 7 is a plan View of the centralpart of a I modified form of stamping from which the -'ex-' pander is made and shows means =providjng'qa modified form of tongue construction ifor in-.

Fig. 8 is a perspective view .of the portion PATENT OFFICE PISTON RING EXPANDER I Ierman Teetor, Hagerstown, Ind., assignor to The Perfect Circle Company, Hagerstown, Ind., a corporation oi lndiana Original No. 2,025,334, dated December 24, 1935, Serial No. 23,477, May 25, 1935. Application for reissue October 21, 1931, Serial No. 170,243

shown in Fig. '7 after the tongue construction is bent into the desired shape;

Fig.9 is a sectional bottom plan view of a piston showing the expander in position behind a piston ring; the section being taken as on the line 9-9 of Fig. 10;

Fig. 10 is a sectional elevation taken through part of a piston and showing expanders behind the rings; 1

Fig. 11 is a top edge elevation of'a somewhat modified form of expanderwith spring leaves of diil'erent lengths and unequally spaced;

Fig. 12 is a perspective view showing 'a modifled form of tongue for insertion in the ring joint; and

Fig. 13 is a perspective view of a portion of a piston ring and a pander. a v

Referring to Figs. 1 to 4, inclusive, the numeral Ill designates aportion of astamping from which the expander is made and which iscom posed of a ribbon of soft steel that may, for

modified tongue on the exexample, have a thicknessvaryin'g' from .005 inch to .020 inch. As indicated, the stampingiscutto provide astrip or band l'i'having a width approximately equal to the width of the ring "groove in which it is used and offale'ngth slightly less than the root diameter of the "ring groove. The I stamping is further cut to provide a plurality of plate portions 12 thatare offset from and spaced alongone side of the strip ll.

' Each of the plate portions llhas a widthsub i stantially equal to thewid'th* of the supporting band ll and is intermediately- 'connected to the band H by a neck l3, so that when theplat'e portions are shaped and the necks are bent there" are provideda plurality of individual' and inde pendently operable spring leaves I! that extend 'in I opposite directions from "the necks" and in overlying juxtaposed relation to the carrier band, that'is to say the leaves are in overlying substantially concentric relation to the band when the band is givenit's circular shape. In order to improve the spring action of the spring leaves It j and to avoid the formation of sharp corners, curved undercuts such as I5 (Fig. 1) may be proleaves l4 are curved or bent as shown in Fig. 2 so as to bring the ring contacting points ,2l thereof as close to the end ofv each spring leaf as possible, but avoiding any'likelihood of the sharp end of the leaf biting into the piston ring. The necks i3 are preferably bent on a pronounced radius as indicated in Fig. 3. The band H is further pressed outwardly from one side thereof to form The.

a plurality of elongated bosses IS in line with the necks I3 50 that the centers of the plate portions I! may have support and bev spaced from the band ll as clearly shown in Figs. 3 and 4.

The strip may also be cut to provide a plurality of suitably shaped and spaced apertures I! through which oil may drain into the crank case of the engine when the expander backs elventilated oil ring.

As shown in Fig. 2, the portion of the hand between the adjacent ends of two of the spring leaves I4 is doubled back on itself to form a projecting tongue l8 and the space between the ends of these particular leaves is less than that between the adjacent ends of the other leaves. The tongue I 8 is preferably diametrically opposite the split or break in the-expander (Fig. 9).

After the soft steel stamping is bent and shaped to its final expander form, the expander is heat treated and tempered so that the steel becomes hard and resilient. I preferably permanently give the expander its circular form,

shift or creep with reference to the ring, which the ring.

though it may be of straight form and then bent circular when placed in the ring groove of a piston.-

As shown in Figs. 9 and 10, when the expander is positioned in a ring groove 23 of a piston 21, the supporting band ll seats against the vertical wall of the ring groove so that the ring contacting points 2| of the spring leaves l4 may properly bear against the inner surface of the piston ring 25 which is appropriately mounted in the groove. The tongue I8 is inserted in the joint between the abutting end faces of the ring, thereby insuring that the expander cannot subsequently would disturb the proper pressure characteristics around the ring and particularly at the ends of The spacing of the ring contacting surfaces 2| around the piston ring provides for the desired pressure characteristics of the ring against the cylinder wall, the greater flexibility of the ring adjacent the joint being taken care of by bringing the contacting surfaces 2| of the spring leavesadjacent the tongue l8 closer together. Each of the spring leaves ll slides freely against the ring and therefore operates with minimum friction, as well as independently of the other leaf springs, so that proper contact between a portion of the ring and an adjacent out-of-round portion of the cylinder bore is thereby assured. The spring leaves fulcrum more or less about the points of their connection with the necks (as at A in Fig. 4) and the bosses l6 limit the tendency of the intermediate part of the plate portions II to move closer toward the supporting band II. p

In Fig. 6 is illustrated a further type of ing construction wherein a pair of spaced, longated bosses 26 are substituted for the si gle boss I6 and in the intermediate part of each pl portion I2 is formed a similar boss 21 that 1 located within the depression between the bosses '26. This arrangement will not only provide the required supDOrt for the spring leaves, but also assure that in the event any one of the curved necks l3 fails, the particular pair of spring leaves ll will not shift their positionlengthwise of the supporting band ll.

The modification shown in Fig. 5 differs from that shown in Fig. 6 only in thatfour circular bosses (II are substituted for the elongated bosses 26 of Fig. 5.

The part of the modified stamping shown in Fig. 7 has a plate portion 32 connected by a some the expander are shorter than the remaining spring leaves. The spring leaves on each half are unequally spaced, the spacing on the two halves however being symmetrical. I have found that this arrangement affords excellent pressure characteristics for some piston rings.

In Fig. 12 is illustrated a modified construction for obtaining a tongue for insertion in a ring joint, wherein a tongue 36 is simply formed by suitably punching the supporting band and bending the punched portion outwardly from the band.

As shown in Fig. 13, the tongue 31, formed by bending the band I I back upon itself, does not extend to the lower edge of the supporting band so that the tongue may extend into the wide upper portion of the joint in the ring and over steps 38 at the ends of the ring.

I claim:

1. A one-piece spring steel piston ring expander comprising a supporting band, leaf portions in overlying substantially concentric relation to the supporting band, necks integral with one edge of said band and one edge of the leaf portions, and

means spacing the leaf portions from the supporting band.

2. A one-piece spring steel piston ring expander comprising a supporting band, leaf portions in overlying substantially concentric relation to the supporting band, necks integral with one edge of said band and one edge of the leaf portions, and

one edged the leaf portions intermediate theends of the latter, and projections in line with the necks spacing the central parts of-the leaf 'portions from the supporting band.

4. A one-piece spring steel pistbn ring expand er comprising a supporting band, leaf portions in overlying relation to the supporting band, necks integrally connected to one edge of said band and one edge of the leaf portions'intermediate the ends of the latter, and bosses on the band and in line with the necks spacing the central parts of the leaf portions from the supporting band.

5. A one-piece spring steel piston ring expander comprising a supporting band, leaf portions in overlying relation to the supporting band; necks curved on a radius and integral with the band and the leaf portions, and projections in line with the necks spacing parts of the leaf portions from the supporting band.

6. A one-piece spring steel piston ring expander adapted to be placed ina piston groovebehind a piston ring and comprising a supporting band, a plurality of circumferentially spaced spring leaves in overlying substantially concentric relation to the supporting band, and portions projecting from the band and integrally connecting theband and said spring leaves, the leaves projecting longitudinally of the band away from said portions with their free ends adapted to engage against the inner periphery of the piston ring.

7. A one-piece spring steel piston ring expander adapted to be placed in a piston groove behind a piston ring and comprising a supporting band, a plurality of circumferentially spaced spring portions in overlying substantially concentric relation to the supporting band, and necks integral- 1y connecting one edge of the band and one edge of the leaf portions intermediate the ends of the latter, the leaf portions forming spring leaves projecting longitudinally of the band away from the necks and adapted to have their free ends bear against the inner periphery of the piston ring. 8. A one-piece spring steel piston ring expander adapted to be placed in a piston groove behind a piston ring and comprising a supporting band, a plurality of circumferentially spaced spring leaves in overlying substantially concentric relation to the supporting band, and portions project-- 1 ing from the band, and integrally connecting the band and said spring leaves, the leaves projecting longitudinally of the band away from said portions with their free ends adapted to engage against the inner periphery of the piston ring, and a projection on the band and adapted to position the expander with respect to the piston ring.

9. A one-piece spring steel piston ring expander adapted to be placed in a piston groove behind a piston ring and comprising a supporting band, a plurality ,of circumferentially spaced spring portions in overlying substantially concentric relation to the supporting band, and necks curved on a radius and integrally connecting one edge of the band and one edge of the leaf portions intermediate the ends of the latter, the leaf portions forming spring leaves projecting longitudinally of the band away from the necks and adapted to have their free ends bear against the inner periphery of the piston ring. a,

10. A one-piece spring steel piston ring ex-.

pander adapted to be placed in a piston groove behind a piston ring and comprising a supporting band, a plurality of circumferentially spaced spring portions in overlying substantially concen-' tric relation to the supporting band, the expander being provided with recesses that define in part necks integrally connecting one edge of the band and one edge of the leaf portion intermediate the ends of the latter, the leaf portions forming spring leaves projecting longitudinally of the band away from the necks and adapted to have their free ends bear against the inner periphery of the piston ring.

11. A one-piece spring steel piston ring adapted to be placed in a groove of a piston member and behind a piston ring member and comprising a supporting band adapted to engage against one of the members, a plurality of circumierentially spaced spring leaves in overlying substantially concentric relation to the supporting band, and portions projecting from the band and integrally connecting the band and spring leaves, the leaves projecting longitudinally of the band away from said portions and adapted to engage against the other of the members.

12. A one-piece spring steel piston ring expander, adapted to be placed in a groove of a piston member and behind a piston ring member and comprising a supporting band adapted to engage against one of the members, a plurality of circumferentially spaced spring portions in overlying substantially concentric relation to the sup porting band, and necks integrally connecting one edge of the band and one edge of the spring portions intermediate the ends of the latter, the spring portions forming spring leaves projecting 'longitudinally of the band away from the necks and adapted to engage against the other of the members.

13. A one-piece spring steel piston ring expander adapted to be placed in a groove of a piston member and behind a piston ring member and comprising a supporting band adapted to engage against one of the members, a plurality of circumferentially spaced spring portions in overlying substantially concentric relation to the supporting band; the expander being provided with recesses that define in part necks integrally connecting one edge of the band and one edge of the leaf portion intermediate the ends of the latter, the leaf portions forming spring leaves projecting longitudinally of the band away from the necks and adapted to engage against the other of the members.

HERMAN TEETOR. 

